A series of trimetallic Prussian blue analogues (PBAs) has been synthesized by adding Fe or Cu to five types of bimetallic PBAs: FeCoPBA, CdCoPBA, CoCoPBA, MnCoPBA, and ZnCoPBA. Such compounds have been characterized by scanning electron microscopy, infrared spectroscopy, and X-ray diffraction measurement. They generally had smaller particle sizes and weaker diffraction peaks than the corresponding bimetallic PBAs. Then, supplementary characterizations on the CuZnCo PBA and CuCdCo PBA showed that the crystallization process, the specific surface area, and the acid sites of the trimetallic PBAs are all different from those of the corresponding bimetallic PBAs. Thermodynamic data obtained by isothermal titration calorimetry indicated that the synthesis of the CuZnCo PBA and CuCdCo PBA is a spontaneous exothermic process with values of enthalpy change in the same range as the corresponding bimetallic PBAs. Such compounds were used as heterogeneous catalysts for the epoxidation of styrene. The results revealed that the catalytic activity of the trimetallic PBA was more efficient than the one of the corresponding bimetallic PBA. Moreover, the experiment of reusability and stability shows that the CuCdCo PBA catalyst is pretty stable.

中文翻译：

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三金属普鲁士蓝类似物的合成及其在苯乙烯环氧化中的催化应用

通过将Fe或Cu添加到五种类型的双金属PBA中来合成一系列三金属普鲁士蓝类似物（PBA）：FeCoPBA，CdCoPBA，CoCoPBA，MnCoPBA和ZnCoPBA。通过扫描电子显微镜，红外光谱和X射线衍射测量来表征此类化合物。与相应的双金属PBA相比，它们通常具有更小的粒径和更弱的衍射峰。然后，对CuZnCo PBA和CuCdCo PBA的补充表征表明，三金属PBA的结晶过程，比表面积和酸位均不同于相应的双金属PBA。通过等温滴定量热法获得的热力学数据表明，CuZnCo PBA和CuCdCo PBA的合成是自发的放热过程，其焓变值与相应的双金属PBA在相同范围内。此类化合物用作苯乙烯环氧化的非均相催化剂。结果表明，三金属PBA的催化活性比相应的双金属PBA之一更有效。此外，可重用性和稳定性的实验表明，CuCdCo PBA催化剂非常稳定。结果表明，三金属PBA的催化活性比相应的双金属PBA之一更有效。此外，可重用性和稳定性的实验表明，CuCdCo PBA催化剂非常稳定。结果表明，三金属PBA的催化活性比相应的双金属PBA之一更有效。此外，可重用性和稳定性的实验表明，CuCdCo PBA催化剂非常稳定。